The present invention relates to an automatic sheet changing system for reprographic machines. The system is applicable for the feed and automatic recovery of sheets in all those reprographic machines in which there is periodically required the changing of sheets, normally of special material, which must be specially protected from dust or light or heat, or from other external agents which could damage them before becoming operative, that is before their use in the machine.
An example of application of the system according to the invention is that where the sheets are photoconductive masters or copy sheets to be employed to form images on ordinary paper in electrophotographic copying machines. In these machines, the latent image of the original to be reproduced is produced on a master sheet of photoconductive material wrapped round a drum or positioned on some other cyclically movable member, is rendered visible by means of known developing operations and is then transferred to a sheet of ordinary paper forming the finished copy of the original after a fixing operation. Each of these masters, depending on the layer of photoconductor of which it is formed, can be used for a number of copying cycles ranging from some hundreds to some thousands, after which it must be replaced.
An object of the present invention is to provide a system for automatically changing sheets such as masters in reprographic machines in which the supply of fresh sheets can be effected by the casual user.